ASTM F1138 : 21

Standard Specification for Spray Shields for Mechanical Joints

Standard Details

1.1 This specification describes the manufacturing requirements for spray shield stock and the fabrication and installation requirements for spray shields made from that stock.

1.1.1 Sections 2 – 14 address the manufacturing requirements for the spray shield stock. Annex A1 addresses the fabrication and installation requirements for the spray shields.

1.1.2 Fig. 1 shows the typical construction of a spray shield. Figs. 2-6 show methods of installation of a spray shield on various mechanical joints.

FIG. 1 Spray Shield Construction (Typical)

FIG. 2 Installation of Butterfly Valve Shield

FIG. 3 Spray Shield for Pump Inlet Head

FIG. 4 Spray Shield for Simplex Strainer

FIG. 5 Spray Shield for Butterfly Valve

FIG. 6 Spray Shield for Valve Bonnet

1.2 The shields are intended for use around mechanical joints (flanged, bolted unions, and so forth) in liquid piping systems with an internal pressure exceeding 26.1 psi (0.18 N/mm²) to prevent the impingement of flammable liquid on hot surfaces or fluids onto electrical switchboards and components resulting from a leak in the mechanical joint, unless otherwise invoked by contractual requirements. Spray Shields are excluded on all suction lines with a head pressure less than 26.1 psi (0.18 N/mm²) and mechanical joints in non-flammable liquid systems in excess of 10 ft of an electrical switchboard, unless otherwise invoked by contractual requirements.2

1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International StandardDetails, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.